This invention relates to a process for producing D-glucuronolactone, more specifically, to a process for producing D-glucuronolactone by oxidizing trehalose and then hydrolyzing the oxidized trehalose.
Various processes are known be capable of producing D-glucuronolactone and many patent applications have been filed in the art. According to an already commercialized process, starch is oxidized with nitric acid and subsequently hydrolyzed to yield D-glucuronolactone. This method has the disadvantage that nitrogen monoxide having no oxidizing power foams in the process of production to interfere with the progress of a homogeneous oxidizing reaction and eventually lower the yield of D-glucuronolactone. In addition, the foaming nitrogen monoxide causes a cubic expansion of the reaction mixture and hence requires a reactor of an increased capacity. Other methods for producing D-glucuronolactone are described In Japanese Patent Publicaiton Nos. 25958/1967 and 5882/1968. These methods have solved the problem of foaming nitrogen monoxide but, on the other hand, no improvement has been made in the yield of D-glucuronolactone which is only about 10-15%.
Japanese Patent Publication No. 7325/1969 discloses a method of producing D-glucuronolactone by the steps of protecting glucose in C-1 position, oxidizing its C-position and subsequently hydrolyzing (deprotecting) the oxidizied glucose. However, the yield of D-glucuronolactone that can be produced by this method is still low (ca. 10-20%) and, in addition, the overall production process is complicated.